Analysis and Detection of Simazine, a Pesticide Used in Sugarcane and Citrus Crops, by Surface Enhanced Raman Scattering (SERS) with Layer-by-Layer (LbL) Thin Films

• Grant number: 24/22018-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: January 31, 2026
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Rafael Jesus Gonçalves Rubira
• Grantee: Lucca Sanches Schimidt
• Host Institution: Instituto de Geociências e Ciências Exatas (IGCE). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

In this scientific initiation project, the pesticide Simazine (SMZ) detection will be investigated using the Surface Enhanced Raman Scattering (SERS) technique. This herbicide belongs to the s-triazine class and has properties that inhibit the enzyme 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) in weeds. It is noteworthy that the pesticide is used in sugarcane and citrus crops in the Rio Claro region, potentially harmful to human health and classified as a toxic agent. In addition to detection via SERS, SMZ will be detected by means of impedance spectroscopy. For this purpose, sensory units composed of Layer-by-Layer (LbL) films containing layers of poly(allylamine hydrochloride) (PAH), a cationic polymer, and gold nanoparticles (Au), which act as anionic components, will be manufactured. These units will be applied in aqueous solutions containing the pesticide SMZ at different concentrations. SERS measurements will be performed directly on the sensor units, allowing for complementary analysis. The potability limits associated with this pesticide (SMZ) are in the order of 10¿¿ mol/L, which makes detection at these concentrations a challenge that requires the use of highly sensitive and selective techniques, such as SERS and impedance spectroscopy. It is important to highlight that this project will serve as a solid foundation for the development of student's skills in several characterization techniques, including ultraviolet-visible (UV-Vis) absorption, infrared spectroscopy (FTIR), Raman scattering, and impedance spectroscopy, preparing them to face future challenges with greater competence and versatility.